Formatting code to display multiple results.

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David 2013-10-29

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https://ww2.mathworks.cn/matlabcentral/answers/104289-formatting-code-to-display-multiple-results

评论： sixwwwwww 2013-10-29

So, I'd like to alter the following code which I have written (Newton's Method), so that it not only outputs the final approximation of the root but each approximation for each iteration of the method. See what I'm saying? How would you suggest that I do this so that it's displayed somewhat neatly in the command window?

function xn = Newton (f, df, xi, tol)
xo = xi; 
xn = xo - f(xo)/df(xo); 
k = 0; 
while ((abs(xn - xo))/(abs(xn)) > tol) 
    if (k <= 100) 
        xn = xo - f(xo)/df(xo); 
        k = k + 1; 
    else
        warning('Maximum number of iterations has been reached') 
        break;
    end
end

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David 2013-10-29

Using fprintf would be best, apparently. However, I have no clue how to use this for data formatting and the help section didn't do much to clear it up.

sixwwwwww 2013-10-29

在 MATLAB Online 中打开

just make a matrix like this

fprintf('Iteration #: %f and approximation value:%f\n', k, xn);

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Answer 1

sixwwwwww 2013-10-29

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/104289-formatting-code-to-display-multiple-results#answer_113622

在 MATLAB Online 中打开

Dear David, you can output iteration number and iteration values as follows:

function [xn, iterations] = Newton (f, df, xi, tol) % output parameter "iteration" store iteration number and iteration values in cell array
xo = xi; 
xn = xo - f(xo)/df(xo);
k = 0; 
while ((abs(xn - xo))/(abs(xn)) > tol) 
    if (k <= 100) 
        xn = xo - f(xo)/df(xo); 
        k = k + 1;
        iteration{k, 1} = k;
        iteration{k, 2} = xn;
    else
        warning('Maximum number of iterations has been reached') 
        break;
    end
end